Break out test and generated lines in branch line total (#13057)

* rm comments

* reduce comment

src/shared/generated-code-path.test.ts

@@ -0,0 +1,72 @@
+import { describe, expect, it } from 'vitest'
+import { isGeneratedCodePath } from './generated-code-path'
+
+describe('isGeneratedCodePath', () => {
+  it('recognizes dependency lockfiles across ecosystems', () => {
+    for (const filePath of [
+      'package-lock.json',
+      'pnpm-lock.yaml',
+      'yarn.lock',
+      'bun.lockb',
+      'Cargo.lock',
+      'poetry.lock',
+      'uv.lock',
+      'Gemfile.lock',
+      'composer.lock',
+      'go.sum',
+      'flake.lock',
+      'mobile/pubspec.lock',
+      'services/api/Pipfile.lock'
+    ]) {
+      expect(isGeneratedCodePath(filePath), filePath).toBe(true)
+    }
+  })
+
+  it('recognizes tool-stamped filename suffixes', () => {
+    for (const filePath of [
+      'api/service.pb.go',
+      // grpc-gateway / protoc-gen-validate stack extra segments onto `.pb.`
+      'api/service.pb.gw.go',
+      'api/service.pb.validate.go',
+      'api/service_pb2.py',
+      'api/service_pb2_grpc.py',
+      'src/schema.gen.ts',
+      'internal/bindings_generated.go',
+      'src/Api.generated.ts',
+      'Forms/Main.Designer.cs',
+      'lib/model.g.dart',
+      'lib/model.freezed.dart',
+      'public/app.min.js',
+      'public/app.js.map',
+      'src/components/__snapshots__/Chip.tsx.snap'
+    ]) {
+      expect(isGeneratedCodePath(filePath), filePath).toBe(true)
+    }
+  })
+
+  it('recognizes generated directories on either separator', () => {
+    expect(isGeneratedCodePath('dist/renderer/index.js')).toBe(true)
+    expect(isGeneratedCodePath('src/__generated__/schema.ts')).toBe(true)
+    expect(isGeneratedCodePath('vendor/github.com/pkg/errors/errors.go')).toBe(true)
+    expect(isGeneratedCodePath('src\\__pycache__\\mod.pyc')).toBe(true)
+  })
+
+  it('leaves hand-written paths alone, including the ambiguous directory names', () => {
+    for (const filePath of [
+      'src/shared/git-branch-line-total.ts',
+      // Excluded on purpose: all common as authored source directories.
+      'build/scripts/release.ts',
+      'target/tracker.rs',
+      'src/out/renderer.ts',
+      'cmd/bin/main.go',
+      // Substrings, not whole segments or suffixes.
+      'src/distributed/queue.ts',
+      'src/vendors/stripe.ts',
+      'src/generator/emit.ts',
+      'docs/generated-code-policy.md',
+      'src/shared/generated-code-path.ts'
+    ]) {
+      expect(isGeneratedCodePath(filePath), filePath).toBe(false)
+    }
+  })
+})